Purpose: Morbid obesity presents numerous challenges in autologous breast reconstruction. Along with considering other medical comorbidities, BMI alone can serve as an overall denominator in the decision-making process to recommend reconstruction
Methods: Retrospective chart review was performed on N = 316 patients who underwent breast reconstruction using DIEP flaps (n=581 flaps). Patients were divided into two groups: patients with BMI < 35 (Group 1, N1=240 patients, n1=438 flaps), and patients with BMI ≥ 35 (Group 2, N2=76 patients, n2=143 flaps). Comorbidities including age, BMI, hypertension, diabetes, autoimmunity, smoking status, previous DVT/PE, and previous abdominal surgery were tracked. Donor site complications including wounds, infection, seroma, hematoma, and DVT/PE, and abdominal bulge were tracked. Flap losses, hospital stay, and completion of reconstruction (receipt of either nipple tattoo or nipple reconstruction) were tracked. Data was collected using a centralized REDCap database. Analysis was performed with SPSS: continuous variables were analyzed with t-tests, and binary variables were analyzed with Chi-Square (χ2). Univariate & multivariate analyses were used to control for group differences.
Results: Age, comorbidities, and past medical histories were equivalent between groups, except for diabetes (Group 1 = 7%, Group 2 = 21%, p<.01) and prior abdominal surgery (Group 1 = 73%, Group 2 = 84%, p=.046). Rates of wounds requiring operation (p=.228), infections requiring IV antibiotics (p=.892), seromas requiring operation (p=.422), hematomas requiring operation (p=.580), pneumothorax (p=.538), DVT (p=.837), and PE (p=.315) were equivalent. Post-op SICU stay (p=.385) and total hospital stay (p=.173) were equivalent. Completion of reconstruction was significantly lower in Group 2 (49%) than in Group 1 (73%), p<.01. Flap loss was significantly higher in Group 2 (3/143, 2.1%) than in Group 1 (3/438, 0.68%), p<.01. Overall flap loss was 6/581 (1.03%).
Conclusion: In our study, DIEP reconstruction in BMI ≥ 35 is associated with three-fold increase in flap loss, and lower likelihood of finishing the reconstruction process. This could be accounted by higher rates of diabetes and prior abdomininal surgery in Group 2, though this was controlled in our analysis. Rate of flap loss was still quite low in Group 2 (2.1%), and this is markedly lower than published rates of implant failure in obese patients (~10-15%). Based on individual practice patterns, patients with BMI ≥ 35 can be educated of their higher risks in consideration as a candidate for free flap breast reconstruction while keeping in mind that there is still a higher likelihood of success when compared to implants.